Dragoon is my opinion, and not just because i main one. Burst damage is a fantastic plus to have, and dragoons bring that to the table. On top of that DRG buff BRD dps, and they, in turn, buff the healers/dps of the raid. DRG is naturally tough,having high defense on their armour and comes with enmity dump, good parry CD, good AoE when needed.

In my opinion this is my ideal DPS comp in a 2/2/4 setup:

DRG/BLM/BRD/(SMN,MNK)

#2 in my books is BRD as they make fights somewhat more forgiving via songs.